Chapter 7, Problem 7A.4E

(a)

Interpretation Introduction

Interpretation:

The speed and kinetic energy for electrons ejected from cesium metal with work function of $2.14eV$ by wavelength of $\text{750}\text{nm}$ has to be calculated.

Concept Introduction:

Work function: Work function of a metal is measure of strength of electrons is held in a metal atom.

$\text{hν}\text{=}\text{KE}\text{+}\text{W}$

Here, W is work function.

KE is kinetic energy.

h is Planck’s constant

$\text{ν}$ is frequency.

Energy can be in the form of kinetic energy or potential energy.  Kinetic energy is the energy associated with motion.

${\text{E}}_{\text{k}}\text{=}\frac{\text{1}}{\text{2}}{\text{mv}}^{\text{2}}$

Here, m- Mass in kilograms

v- Velocity in meters per second.

(b)

Interpretation Introduction

Interpretation:

The speed and kinetic energy for electrons ejected from cesium metal with work function of $2.14eV$ by wavelength of $\text{250}\text{nm}$ has to be calculated.

Concept Introduction:

Work function: Work function of a metal is measure of strength of electrons is held in a metal atom.

$\text{hν}\text{=}\text{KE}\text{+}\text{W}$

Here, W is work function.

KE is kinetic energy.

h is Planck’s constant

$\text{ν}$ is frequency.

Energy can be in the form of kinetic energy or potential energy.  Kinetic energy is the energy associated with motion.

${\text{E}}_{\text{k}}\text{=}\frac{\text{1}}{\text{2}}{\text{mv}}^{\text{2}}$

Here, m- Mass in kilograms

v- Velocity in meters per second.